genius who set the stage for pop music, left a lasting imprint on generations of performers, but despite the late singer's unparalleled talent, jackson's legacy was tarnished by addiction, his loneliness, the ultimate scandal, and now a revealing new book is shedding fresh light on his private struggles, so here's abc's nick watt. ♪ thriller >> there hasn't been anyone that famous in a single moment as he was during "thriller" time. i think that was probably the peak of celebrity for a human being. >> reporter: randall sullivan, the highly acclaimed journalist, spent three years getting behind the mask of the most celebrated entertainer our world has ever known. it's a tale of family, fame, lost childhood and startling accusations that you won't have heard before. the portrait of a prescription drug addict who could spend $250,000 on a shopping spree without thinking.